Insert attachments by uploading files hangs editor

Summary

• When adding files through the import option, the file will be uploaded as an attachment but not displayed in the editor. Besides that, Confluence will allow the user to Publish the page.

Steps to Reproduce

1. Open the editor;
2. Click on + >> Files and Images
3. Upload a file
4. Click on Insert

Expected Results

• Confluence would show the file inserted into the editor.

Actual Results

• Confluence doesn't show the file inserted and the button Publish no longer works.

Workaround

• Uploading and inserting a file by drag & dropping works normally.